The composition of this invention is a plasticized sulfur coating comprising at least 50% by weight sulfur. The invention concerns the use of organosilanes in combination with finely divided particulate mineral suspending agents to improve the chemical resistances of the plasticized sulfur coatings.
Plasticized sulfur-based coating compositions are well known. Generally, they comprise at least 50% by weight sulfur, a sulfur plasticizer, and a filler. For instance, U.S. Pat. No. 4,026,719 granted May 31, 1977 to Simic describes plasticized sulfur coating compositions comprising sulfur, a plasticizer, and a mineral filler. In addition, U.S. Pat. No. 4,026,719 summarizes several articles and other patents which teach various plasticized sulfur compositions comprising sulfur, a plasticizer, and a filler.
In addition to the three principal ingredients, plasticized sulfur coating compositions may also comprise dyes or pigments, aggregate such as gravel, rock, or sand or the like. Each of these additional optional ingredients adapts the coating to a particular use. For instance, the addition of sand to a typical plasticized sulfur coating provides a textured appearance particularly desirable when the coating is applied as a surface bonding material on the exterior of a building. Gravel or rock is used to adapt the plasticized sulfur coating for use as roadbed coating similar to concrete or asphalt.
As a rule, the mechanical properties of plasticized sulfur compositions have been altered by varying either the plasticizing system, sometimes by adding a viscosity increasing or reducing agent, or the filler or both. Thus, for instance, U.S. Pat. No. 3,823,019 granted July 1974 to Dale et al teaches plasticized sulfur compositions specifically comprising dicyclopentadiene, glass fiber, and talc. Similarly, U.S. Pat. No. 4,026,719 teaches plasticized sulfur composition specifically containing a mica filler.
While the mechanical properties of plasticized sulfur coating compositions can be adapted and optimized by varying the plasticizer or the filler to fit the specific end use, the final coatings nonetheless tend to lose strength during use, especially under exposure to strong chemical action as in the floors and walls of an acid pit. Accordingly, it would be advantageous to provide a composition which could be adapted to a specific use by the selection of an appropriate plasticizer and filler and could be stabilized against the tendency to lose strength during chemical attack.